<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>初始化username数据</h1>
<c:set var="username" value="黄斌"></c:set>
<c:out value="${username }"></c:out>
<h1>重新对username进行赋值</h1>
<c:set var="username" value="张俊林"></c:set>
<c:out value="${username }" default="巷子拉克"></c:out>
<h1>将username进行remove</h1>
<c:remove var="username"></c:remove>
<c:out value="${username }" default="巷子拉克"></c:out>
</body>
</html>